Living in a throbbing metropolis such as Karachi, the rattling of buses on the roads, the incessant blaring of horns, the constant whirring of the rickshaws, coupled with the omnipotent cloud of pollution hanging over us are things which we simply have surrendered to.

We raise a hue and cry about pollution — be it air or noise — well aware that it is a cause for grave health concerns. Air pollution results in aggravated cardiovascular and respiratory illnesses. Noise pollution may result in seemingly trivial ailments such as sleep disturbance and annoyance and even lead to hearing impairment, hypertension, ischemic heart disease, changes in the immune system and birth defects.

However, it is not just the body that is susceptible to damage at the hands of noise and air pollution. According to a recently published research which followed nearly two million people in the Canadian province of Ontario over 11 years (between 2001 and 2012), air pollution or noisy traffic could be contributing to mental disorders as well. The study was published in the Lancet — one of the world’s oldest and best known general medical journals.

Studies show that people living near busy roads are more prone to develop mental disorders

Among the illnesses caused by pollution is dementia, a disease marked by memory loss, personality changes and impaired reasoning. Nearly 50 million people around the world suffer from dementia. About 243,611 cases of dementia were diagnosed during the study, but the risk was greater among those living close to major roads. In this large population-based cohort, living close to heavy traffic was associated with a higher incidence of dementia.

According to Dr Jawad Chistie, a prominent environmentalist and principal consultant at Subhe Nau, a non-profit engaged in conserving nature and improving public health, the link between dementia and air pollution is not something to be taken lightly.

“The science to prove such links is not easy and generally takes many years, if not decades,” argues Dr Chistie. “Just like public health experts spent about a full 100 years before they could come up with ‘conclusive evidence’ that smoking causes cancer. The studies to suggest the link were there, and people also knew that smoking could cause cancer, but convincing governments, and the tobacco industry, proved to be extremely difficult.”

The environmentalist explains that besides dementia, there are many other diseases such as multiple sclerosis that have been suspected of having an aetiology linked to pollution, or more generally, environmental causes. “Common air pollutants such as PM 2.5, PM 10 and NOx (fine particulate matter and nitrogen oxide) are all leading to major problems, including harmful gases that people are exposed to living near major highways,” he continues.

Previously, scientists have linked air pollution and traffic noise to reduced density of white matter and lower cognition. A recent study suggested that magnetic nano-particles from air pollution can make their way into brain tissue.

Professor Caleb Finch at the USC Leonard Davis School of Gerontology says, “Microscopic particles generated by fossil fuels enter our body directly through the nose into the brain. Cells in the brain treat these particles as invaders and react with inflammatory responses, which, over the course of time, appear to exacerbate and promote Alzheimer’s disease.”

According to Dr Qurat Khan, assistant professor at the department of psychiatry at the Aga Khan University Hospital, noise and pollution are important contributors to the environment which play a vital role in the bio-psycho-social model of psychiatric conditions. They may cause unmasking and manifestation of psychiatric conditions such as anxiety, depression, bipolar illnesses, psychotic illnesses and may also cause agitation, irritability, and restlessness among people, especially those who are vulnerable.

According to Dr Qurat Khan, assistant professor at the department of psychiatry at the Aga Khan University Hospital, noise and pollution are important contributors to the environment which play a vital role in the bio-psycho-social model of psychiatric conditions. They may cause unmasking and manifestation of psychiatric conditions such as anxiety, depression, bipolar illnesses, psychotic illnesses and may also cause agitation, irritability, and restlessness among people, especially those who are vulnerable.

When asked if this may be the reason doctors advise people to move to quieter areas to recuperate from stress, she says: “Increased work-load, multi-tasking as well as noise and air pollution may cause mental exhaustion, stress and fatigue. Moving away from these and other stressors, along with engaging in exercises such as relaxation and meditation, may help one recuperate.”

Dr Chistie also mentions that in the case of Pakistan, the development versus the environment debate continues to rage. “The easy answer to which is to allow people to suffer, literally die, while unabashed ‘development’ continues. We know very well that this development is actually nothing but private business interests that governments want to promote at the expense of the health of the nation.”

He laments that over the years, governments and businesses have forgotten the ‘precautionary principle’ which is just common sense — don’t get into something that may cause damage to the health of not only people, but also other species. “It is being increasingly learnt from research that major highways may not be the answer to burgeoning populations and economic activity. Smaller, self-sufficient town planning, with good public transport is the way to go,” he says.

It is certainly alarming that according to the World Health Organisation three million people die every year due to outdoor air pollution.

The rise in population and urbanisation has resulted in people living close to heavy traffic and even a modest effect from near-road exposure could pose a large public health burden. It is tragic that air pollution is not taken into consideration in urban planning and building design to reduce exposure.

This just might be the proverbial last straw on the camel’s back to prove why life in urban centres continues to get more stressful. More than ever we need to clean up the air.

Published in Dawn, EOS, May 7th, 2017